Which hematoxylin solution is best used within a few days after preparation?

• A. Weigert's
• B. Harris'
• C. Gill's
• D. Mallory's

Answer: (A)

Hematoxylin solutions differ in how long they stay usable after preparation; some are best used very soon after making them.

Weigert's hematoxylin is particularly sensitive to aging. Once prepared, it oxidizes and can begin to degrade or precipitate, which leads to variable staining and weaker or inconsistent nuclear coloration if you wait too long. Using it within a few days helps ensure a strong, crisp nuclear stain with the intended contrast when paired with the iron mordant.

Other formulations like Harris', Gill's, or Mallory's are more stable under typical storage conditions, so they can be kept longer as working solutions.